Heat transfer system controls



My 1969' P. R. HUGHES ET AL HEAT TRANSFER SYSTEM CONTROLS 2 Sheets-Sheet 1 Filed Nov. 5, 1967 11v VEW TORS PAUL R. HUGHES THOMAS J. LORD THE/R. ATTORNEY.

July 22, 1969 P. R. HUGHES ET AL 3,45 5

HEAT TRANSFER SYSTEM CONTROLS 2 Sheets-Sheet 2 Filed Nov. 5, 1967 FIG-6 INVENTORS PAUL R. HUGHES THOMAS J. LORD u W F THE/R ArrRNEK Stt$ U.S. Cl. 137565 11 Claims ABSTRACT OF THE DISCLOSURE A self-acting valve in a system using a primary source of fluid as a coolant and using a secondary source of fluid in an alternate or supplemental sense, the valve having self-closing characteristics and being releasably held in a closed position against the effects of pressure differences on opposite sides thereof.

This invention relates to heat transfer systems, and particularly to a system in which flow of an alternate or secondary cooling fluid is controlled by valve means.

An object of the invention is to integrate secondary cooling means with heat transfer apparatus to present a package equipped for cooling of a transfer fluid by reference to a primary or secondary cooling fluid or to a combination of the two.

Another object of the invention is to insure closing of an alternate air source duct in a heat transfer system during what may be considered a normal operation in which the system is supplied with a primary source of cooling A further object of the invention is to provide a generally new valve construction unbalanced for flow responsive opening and assuming normally a closed position.

Still another object of the invention is to control valve opening and the operation of blower means to draw on the second source cooling air at the same time.

A still further object of the invention is to provide a generally new valve construction functioning as described and including features of operation and control insuring proper opening and closing movements of the valve and providing for its simplified assembly and adjustment.

ther objects and structural details of the invention will appear from the following description, when read in connection with the accompanying drawings, wherein:

FIG. 1 is a view in side elevation, partly broken away and partly in diagrammatic form of an integrated heat transfer unit in accordance with the illustrated embodiment of the invention;

FIG. 2 is a top plan view of the unit of FIG. 1;

FIG. 3 is a rear view of the unit of FIG. 1;

FIG. 4 is a detail view in side elevation, partly broken away, of the valve and latch mechanism, showing the valve latched closed;

FIG. 5 is a view in longitudinal section through the valve body, the valve member being shown in full;

FIG. 6 is a detail view similar to FIG. 4 taken from a diflerent angular position and broken away to show the mounting of the valve;

FIG. 7 is a detail view like FIG. 4, showing the latch released and the valve full open;

FIG. 8 is a view like FIG. 4, taken in front elevation and turned angularly relatively to FIG. 4; and

FIG. 9 is a fragmentary, detail view of a manifold member, showing the opening receiving the valve housing.

Although not so limited, the invention in its illustrated form is adapted for use in aircraft where it is concerned with the cooling of a transfer fluid in the form of a liquid coolant which is. cycled for cooling purposes to and from ice a heat source, as for example, operating electronic equipment. The liquid transfer fluid absorbs heat from the heat source and in turn releases heat energy in the heat transfer system of the present invention. External air under pressure, as for example, cabin air, produces a primary flow of cooling air during aircraft flight. On the ground, a secondary source is drawn upon, a blower generating a forced air flow. The instant invention provides an integrated unit in which the transfer fluid is brought into heat exchange relation to either the primary or secondary air flows under conditions obviating loss of pressure and misoperation due to pressure differentials.

In the unit, a heat exchanger 10 provides surfaces for the conduct of heat from the transfer liquid to the flowing air. The heat exchanger is of a generally known plate and fin type comprised of stacked core sheets 11 suitably formed and related one to another as to provide a plurality of flow passages 12 (FIG. 1) for the transfer liquid and, in cross flow relation to the passages 12 a plurality of air flow passages 13 (FIG. 2). Heat is conducted through separating core sheets from the liquid to the relatively cooler air. Fin material 14 in the passages 12 and other fin material 15 provide extended heat transfer surface and lend structural rigidity to the assembly. The passages 12 are closed at their one ends. Intermediately disposed in each such passage is a nose piece 16 extending from one end of the passage toward but short of the other end. The effect is to divide each passage 12 into upper and lower portions. These communicate at the said one end thereof with respective manifolds 17 and 18 welded or otherwise secured to one side face of the heat exchanger. That side face, comprised in part of the nose pieces 16 and in other part of members 19 closing the ends of air flow passages 13 provides a surface for attaching adjacent ends of the manifolds 17 and 18 in a manner to segregate the manifold interiors. The liquid transfer fluid is directed from the heat source to unit 10 where it enters manifold 17 by way of an inlet opening 21. Within manifold 17, the liquid flows through the upper portions of passages 12, around opposite ends of the nose pieces 16 and back through the bottom portions of passages 12 to manifold 18. An outlet 22 from manifold 18 provides for return flow to the heat source and recycling.

Flow of the cooling air is relatively unconfined. Upper and lower faces of the heat exchanger assembly are open so that air may flow freely through the passages 13 from the upper side thereof, as viewed in FIG. 1, and out of the lower side. Heat energy absorbed by the flowing fluid is transferred thereby to ambient surroundings or otherwise suitably dispersed.

Mounted to the upper face of the heat exchanger unit 10, in a closing relation thereto, is a manifold 23 defining an interior plenum chamber 24.

Under conditions to be described, the chamber 24 is supplied with a flow of cooling fluid from a source 25 or from a source 26 or from a combination of the two. An upper opening 27 in manifold 23 is surrounded by a flaring flange 28 and communicates through a conduit 29 with source 25. The manifold has a lateral opening 31 (FIG. 9) closed by a flange 32 on a housing member 33. To an outwardly facing end of the latter is bolted a cylindrical duct 34. A conduit 35 communicates source 26 to duct 34. In accordance with the described illustrative embodiment of the invention the source 25 may be considered to be cabin or cockpit air which under flight condi tions is pressurized. Means, for example a pressure regulating valve 36, may be provided in conduit 29 to control the rate of flow to chamber 24 and to inhibit reverse flow. Source 26 may be any conveniently accessible source wherein air is available under non-flight conditions, as for example wheel wells.

Within the cylindrical duct 34 is an electrically energizable motor 37 longitudinally disposed therein to present a driven shaft 38 coaxial with duct 34. Spaced ribs 39 (one shown) position the motor 37. Secured to the shaft 38 is a hub 41 on which is formed peripheral fan blades 42. The fan blades are so formed and the assembly comprising hub 41 and blades 42 is so positioned on shaft 38 that rotation of the shaft in response to energizing of motor 37 draws air into the duct 34 from the outer end thereof and propels it through and beyond its open inner end. Such inner end of the duct 34 has an external flange 43 secured by means of clamps 44 and bolts 45 to the outer projecting end of housing 33. The latter is formed with a through longitudinal bore 46 in aligned communicating relation to the duct 34. Operation of motor 37 and its attached fan assembly accordingly delivers air from source 26 through the housing 33 to plenum chamber 24.

The inner end of the housing 33 projects beyond flange 32, through opening 31, into the plenum chamber. There its extremity may have the angular configuration indicated in order to accommodate valve movement as well be described, while offering a minimum of interference to a free flow of air to and through the heat exchanger passages 13. The arrangement further is one obviating additional projection of the housing 33 externally of the manifold 23 thereby reducing exterior dimensions. Within the inner projecting end of housing 33 are diametrically opposed openings accommodating a shaft 47. In intersecting relation to bore 46, the shaft 47 is thus journaled in the inner end of the housing 33 for relative rotary motion. Offset from the axis of bore 46, the shaft 47 provides a mounting for a blade-like butterfly valve 48. A screw 49 provides for a rigid attachment of the valve blade to the shaft. The valve blade 48 has a slightly elliptical configuration, curving from a minor axis approximately corresponding to the internal diameter of bore 46 to a major axis 90 distant somewhat exceeding the internal diameter of the bore. As a result, when installed in the bore 46 in what may be considered a closed position diametrically opposed edges of the blade in its major axis contact and limit against the wall bore, causing the blade to assume an inclined position as shown. Remaining peripheral portions of the blade achieve an approximate touching contact with the wall bore so that the fit of the valve in the housing 33 is relatively close, in a manner to block any appreciable flow of fluid through the housing in a closed position of the valve. The described limiting edges of the valve blade may advantageously be beveled in opposing senses, as shown, for more effective sealing engagement with the bore wall. By reason of the offset mounting of the shaft 47, the valve blade 48 has an unbalanced character, a larger expanse thereof being presented to one side of the shaft than the other. A flow of air through the housing 33 accordingly finds the valve 48 able to respond thereto by moving away from or toward a closed position, by virtue of the relatively unbalanced moment arms created by the structural imbalance resulting from the valve mounting. A fully open position of the valve finds it positioned generally parallel to the axis of housing 33, substantially as shown in FIG. 7.

At what may be considered its upper end the shaft 47 projects through and beyond housing 33 and has a bushing 52 fixed to its projecting end, as by being pinned thereto. A torsion spring 53 surrounds the bushing 52, having one end thereof atached to a flanged end of the bushing and its other end suitably anchored in the housing 33. According to the construction and arrangement of the parts, opening of the valve blade 48 as by moving it from the closed position of FIGS. 4, and 6 to the open position of FIG. 7, stresses the spring 53 storing therein mechanical energy which when released returns the valve blade toward closed position.

The opposite end of shaft 47 also projects through and beyond hou ing 33. On i s extremity is a flanged head 54 serving as a cam or latch plate. In the periphery of member 54 is a cutout portion comprising a substantially radial shoulder 55 and a surface 56 connecting shoulder 55 to the circular periphery of the member 54. A latch member 57 has a hooked end 58 adapted to ride the periphery of member 54 and engage shoulder 55, limiting rotation of shaft 47 in one direction. The latch member or arm 57 extends through an opening 59 in the housing fiange 32. Its end opposite hooked end 58 is turned over and slotted and terminates in an embossment 61 integral with and in effect suspended from housing 33. Intermediate its ends the latch arm 57 has an attached bushing 62 receiving a stud 63 eccentrically disposed on the end of a stub shaft 64 mounted in the embossment 61. The opposite end of the stub shaft 64 is accessible for turning adjustment whereby the eccentrically positioned stud 63 may effect incremental bodily adjustments of the latch arm 57.

A position of the interior of embossment 61 is threaded for mating engagement with an externally threaded end of a solenoid unit 65. Electromagnetic means of a known kind within solenoid 65 is effective when energized to retract a plunger 66, the latter projecting into embossment 31 and having a pin in slot connection with the inner end of latch arm 57 whereby the latch arm may be withdrawn relatively to plunger 66 but when engaged responds to a reciprocating motion of the solenoid plunger by rocking in an oscillatory sense about stud 63 as a pivot. The arrangement is one to position the hooked end of latch arm 57 to effective and ineffective positions of engagement relative to the shoulder 55 of latch plate 54. A clamp strap 67 surrounds the solenoid 65. The ends of the clamp cooperate with an car 68 integrally formed on an end of embossment 61, the clamp being tightened upon the solenoid to prevent its rotary motion relative to the housing 33 by tightening a bolt 69. Loosening of the bolt allows for rotary adjustment of the solenoid unit in order that it may be bodily shifted in an endwise sense. This motion, accomplished relatively to the plunger 66, serves to vary compression of the conventional spring contained in the solenoid unit to project plunger 66 upon deenergizing of the unit. Thus, rocking motion of the latch arm 57 in a direction to engage hooked end 58 with the periphery of latch plate 54 is a function of spring pressure whereas movement of the latch arm in an opposite or disengaging direction is a positive function of solenoid energization and consequent retraction of plunger 66. Rotary adjustment of the unit 65, as described, insures that the solenoid contained spring has sufficient tension to assure latching but is yet light enough to avoid excessive frictional forces as might inhibit valve closure.

The valve blade 48 is limited in its motion in a clockwise sense, as viewed in FIG. 4, by engaging the wall of bore 46. The shaft 47 and its flanged head 54 are so oriented in a rotary sense that with the valve blade in a closed position abutment shoulder 55 is presented for engagement with the hooked end 58 of latch arm 57. With the valve closed, therefore, and the solenoid unit 65 deenergized, the blade 48 positively is prevented from rotating in either direction and flow through housing 33 in either direction is denied.

In the operation of the system under what may be considered normal conditions, that is with the aircraft in flight, the valve parts occupy the positions shown in FIG. 4 with valve 48 closed and latched in a closed position, solenoid unit 65 being deenergized. Cooling air for heat exchanger unit 10 accordingly is at this time supplied plenum chamber 24 from source 25. Motor 37 is deenergized and there is no flow to duct 34 from source 26. The closed valve 48 maintains plenum chamber 24 substantially sealed, obviating any appreciable loss of pressure from chamber 24 by reverse flow past the valve. In this connection, higher pressures in plenum chamber 24 as applied to the unbalanced valve 48 tend to rock the valve in a clockwise direction but motion of the valve in this direction is precluded by the elliptical configuration of the valve as described. Motion of the valve in the opposite or counterclockwise direction as viewed in FIG. 4 positively is prevented by latch arm 57.

Under non-flight conditions or when it may otherwise be desirable to draw upon the source 26 either for supplemental or for replacement purposes, electric motor 37 and solenoid unit 65 are energized in what may be a simultaneous operation either manually or automatically initiated. Thus, motor 37 and solenoid unit 65 may be associated in an electrical circuit closed manually, or automatically as in response for example to landing of the aircraft. In any event, the result is to begin rotation of fan means 41 and 42 and at about the same time to retract plunger 66, rocking arm 57 in a direction to release latch plate 54. In response to these occurrences a flow of air under pressure is induced through duct 34 and housing 33 and into plenum chamber 24 in the process of which valve 48 is forced open. In the opening process, spring 53 is stressed and attempts to return the valve toward closed position. The valve continues, however, to be held open by the generated air flow until operation of motor 37 is discontinued. The valve is then released to control of the spring 53 which rocks it toward a closed position and may in fact move it to a fully closed position to be engaged and held by latch arm 57. The valve is in any event fully closed in the presence of continued air flow from source 25, or upon resumption of such air flow, by the pressure of air in plenum 24 acting upon the front face of valve 48. Shutting off of motor 37 is accompanied by deenergizing of solenoid unit 65. The latch arm 57 accordingly is released to be urged by spring pressure in a direction to engage the hooked end 58 with the periphery of latch plate 54. As this plate turns to position abutment shoulder 55 to the rear of hooked end 58, the latch arm moves in front of to engage such shoulder. Fine adjustments of the latch arm, as may be required for timely and full engagement of the hooked end 58 with shoulder 55, is accomplished by rotary adjustment of stub shaft 64, revolubly positioning the eccentric stud 63. A proper adjustment of shaft 64 will find arm 57 latching valve 48 closed in a position permitting no appreciable play or lost motion. In a closed, latched position of the valve minimum opportunity is afforded for fluid flow in either direction thereby. Thus, the feature of latch arm adjustment assures a lock tight enough to avoid valve play, the latitude of adjustment 'being such, however, that disengagement of the latch arm is assured when the solenoid unit energizes. Adjustment in conjunction with the solenoid spring provides that pressure of latch arm ree'ngagement upon deenergizing of the sole noid is not so great as to restrict a return motion of the valve to closed position.

The valve closing spring 53 is selected to provide sufficient tension to assure closing and to overcome latch arm drag while being sufliciently weak as not to prevent opening of the valve in response to fan operation.

The inner extremity of housing 33 is formed with an upturned lip 71 just cleared by a peripheral portion of valve 48 as the valve moves from a closed to an open position. The lip serves an air deflecting and turbulizing function opposing any tendency of the valve to stop its opening movement in a partly opened position. Thus, in opening, after the adjacent peripheral portion of the valve 48 passes lip 71 a portion of the flowing air encounters the lip and is deflected thereby directly upon the rear or underlying surface of the valve blade. The result is to counteract created flow-pressure effects which may bring on a static condition of the valve, interfering with its smooth continuing movement from a closed to a fully open position.

The housing 33 with its mounted parts and the fan and motor assembly with enclosing duct 34 comprise a unitary sub-assembly which as noted is installed through the side of manifold 23 to project in part outside the manifold and in part within it. The flange 32 on housing 33 engages the exterior of manifold 24 in a surrounding relation to opening 31 therein. A gasket 72 is interposed in a sealing relation between flange 32 and the manifold. From the manifold 32 to the outer end of housing 33 the exterior of the housing is formed with circumferentially spaced radial ribs 73. Bolts 74 extend through the ribs 73 and through the side walls of manifold 23 in an adjacent relation to opening 31. On the inner wall of the manifold are installed clinch nuts 75 in which bolts 74 engage. The result is to achieve a secure mounted relation of the described sub-assembly to the manifold 23.

The opening 31 has opposed key enlargement 76 providing clearance for the projecting ends of shaft 47. The embossment 61 has a flange 77 projecting oppositely to solenoid 65. It mounts an electrical receptacle 78 from which extend leads 79 to the motor and to the solenoid.

What is claimed is:

1. In a system of heat transfer wherein an inlet manifold of a heat exchanger is normally supplied with fluid from a first source and is selectively supplied with auxiliary or secondary fluid from a second source; means controlling the supply of fluid from said second source, including a duct installed in to communicate with said manifold, normally deenergized energizable means to induce flow of second source fluid through said duct into said manifold, a normally closed valve in said duct responding to fluid flow induced by energizing of said energizable means by moving to an open position, means for latching said valve in a closed position preventing opening of said valve under the influence of relatively higher second source fluid pressure not resulting from energizing of said energizable means, and selectively operable means concomitantly to disable said latching means and to energize said energizable means.

2. Control means according to claim 1, characterized in that said duct is installed to have an inner end project into said manifold and an outer end projecting outwardly thereof, said energizable means comprising afan and motor combination received in one end of said duct to cause when energized a flow of fluid in said duct from its outer to its inner end, said valve being a butterfly valve mounted in the other end of said duct and spring biased to a closed position, said valve being mounted in an unbalanced condition to respond to the pressure of flowing fluid in said duct by moving to an open position.

3. Control means according to claim 2, wherein said butterfly valve has a shaft rotatable to position said valve, characterized in that said latching means includes a latch plate on said shaft and alatch member releasably engaging said latch plate.

4. Control means according to claim 1, characterized in that said valve is a butterfly valve mounted in said duct for oscillatory motion therein, movement of said valve in one direction being limited to a position closing said duct, said valve being unbalanced so that a pressure in said duct greater than that in said manifold tends to open the valve while a reverse pressure difference tends to close the valve.

5. Control means according to claim 4, characterized in that said duct defines a cylindrical interior while said valve is received in said duct and has an eliptical outline with its major axis exceeding the internal diameetr of said duct and its minor axis substantially corresponding to said diameter whereby said valve in closing assumes an inclined position in said duct with its periphery contacting the internal wall of the duct.

6. Control means according to claim 5, characterized in that the periphery of said valve has opposing bevel configurations whereby the contact thereof with the duct wall is a substantially sealing engagement.

7. Control means according to claim 4, characterized by spring means biasing said valve to closed position.

8. Control means according to claim 4, characterized by fluid flow deflecting means in said duct located in a position beyond said valve in a closed position of the valve having regard to flow of the second source fluid and operative in a partly open position of the valve to direct flowing fluid upon said valve in a valve opening direction.

9. Control means according to claim 1 wherein said valve is rotatable in opposed senses to open and closed positions, characterized in that said latching means includes a rotary latch plate having a peripheral notch therein formed at one end with an abutment shoulder and extending therefrom to its other end as an inclined surface, said latching means further including a latch member having a hook-like extremity riding the periphery of said latch plate, engagement of said member with said shoulder positively limiting rotation of said valve in one direction, disengagement of said latch member disabling said latch means.

10. Control means according to claim 9, characterized by means limiting rotation of said valve in the opposite direction, said last named means defining a closed position of said valve, said latch member and said latch plate being relatively positioned so that the hook-like extremity of said member engages in said notch substantially in contact with said shoulder in said closed position of said valve whereby said latching means and said limiting means cooperate in positively holding said valve in a closed position irrespective of pressure differences on opposite sides thereof.

11. Control means according to claim 10, characterized by means for adjusting said latch member for optimal cooperation with said latch plate.

References Cited UNITED STATES PATENTS 4/1950 Ott 165-124 9/1960 Morrison et al. 23017 U.S. Cl. X.R. 165-24; 251-116 

